now = int(input())

if now >= 30:
    print('Yes')
else:
    print('No') now = int(input()) now int(input()) int input() input if now >= 30:
    print('Yes')
else:
    print('No') now >= 30 now 30 print('Yes') print 'Yes' print('No') print 'No' now = int(input()) int(input()) now
now = int(input())

if now >= 30:
    print('Yes')
else:
    print('No')
